You can have a very intense relationship with fictional characters because they are in your own head.

Oh, HONESTLY, don't you two read?

... you could claim that anything's real if the only basis for believing in it is that nobody's proved it doesn't exist!

Just — just to be clear,” he said. “You want to leave Tonks at her parents’ house and come away with us?” “She’ll be perfectly safe there, they’ll look after her,” said Lupin. He spoke with a finality bordering on indifference. “Harry, I’m sure James would have wanted me to stick with you.” “Well,” said Harry slowly, “I’m not. I’m pretty sure my father would have wanted to know why you aren’t sticking with your own kid, actually.

I am proud of having done what I've done. Very proud.

She's as nutty as squirrel poo.

You're a wizard, Harry.